src/surf/maxmin.c

   1 /* Authors: Arnaud Legrand                                                  */
   2
   3 /* This program is free software; you can redistribute it and/or modify it
   4    under the terms of the license (GNU LGPL) which comes with this package. */
   5
   6 #include "xbt/sysdep.h"
   7 #include "xbt/error.h"
   8 #include "maxmin_private.h"
   9 #include <stdlib.h>
  10
  11 /* extern lmm_system_t Sys; */
  12 /* extern lmm_constraint_t L1; */
  13 /* extern lmm_constraint_t L2; */
  14 /* extern lmm_constraint_t L3; */
  15
  16 /* extern lmm_variable_t R_1_2_3; */
  17 /* extern lmm_variable_t R_1; */
  18 /* extern lmm_variable_t R_2; */
  19 /* extern lmm_variable_t R_3; */
  20
  21
  22 lmm_system_t lmm_system_new(void)
  23 {
  24   lmm_system_t l = NULL;
  25   s_lmm_variable_t var;
  26   s_lmm_constraint_t cnst;
  27
  28   l = xbt_new0(s_lmm_system_t, 1);
  29
  30   xbt_swag_init(&(l->variable_set),
  31                 xbt_swag_offset(var, variable_set_hookup));
  32   xbt_swag_init(&(l->constraint_set),
  33                 xbt_swag_offset(cnst, constraint_set_hookup));
  34
  35   xbt_swag_init(&(l->active_constraint_set),
  36                 xbt_swag_offset(cnst, active_constraint_set_hookup));
  37
  38   xbt_swag_init(&(l->saturated_variable_set),
  39                 xbt_swag_offset(var, saturated_variable_set_hookup));
  40   xbt_swag_init(&(l->saturated_constraint_set),
  41                 xbt_swag_offset(cnst, saturated_constraint_set_hookup));
  42
  43   return l;
  44 }
  45
  46 void lmm_system_free(lmm_system_t sys)
  47 {
  48   lmm_variable_t var = NULL;
  49   lmm_constraint_t cnst = NULL;
  50
  51   while ((var = extract_variable(sys)))
  52     lmm_var_free(sys, var);
  53
  54   while ((cnst = extract_constraint(sys)))
  55     lmm_cnst_free(sys, cnst);
  56
  57   xbt_free(sys);
  58 }
  59
  60 void lmm_variable_disable(lmm_system_t sys, lmm_variable_t var)
  61 {
  62   int i;
  63   lmm_element_t elem = NULL;
  64
  65   for (i = 0; i < var->cnsts_number; i++) {
  66     elem = &var->cnsts[i];
  67     xbt_swag_remove(elem, &(elem->constraint->element_set));
  68     if (xbt_swag_size(&(elem->constraint->element_set)))
  69       make_constraint_inactive(sys, elem->constraint);
  70   }
  71   var->cnsts_number = 0;
  72 }
  73
  74 static void lmm_var_free(lmm_system_t sys, lmm_variable_t var)
  75 {
  76
  77   lmm_variable_disable(sys, var);
  78
  79   xbt_free(var->cnsts);
  80   xbt_free(var);
  81 }
  82
  83 static void lmm_cnst_free(lmm_system_t sys, lmm_constraint_t cnst)
  84 {
  85 /*   xbt_assert0(xbt_fifo_size(&(cnst->row)), */
  86 /*               "This list should be empty!"); */
  87   remove_active_constraint(sys, cnst);
  88   xbt_free(cnst);
  89 }
  90
  91 lmm_constraint_t lmm_constraint_new(lmm_system_t sys, void *id,
  92                                     xbt_maxmin_float_t bound_value)
  93 {
  94   lmm_constraint_t cnst = NULL;
  95   s_lmm_element_t elem;
  96
  97   cnst = xbt_new0(s_lmm_constraint_t, 1);
  98   cnst->id = id;
  99   xbt_swag_init(&(cnst->element_set),
 100                 xbt_swag_offset(elem, element_set_hookup));
 101   xbt_swag_init(&(cnst->active_element_set),
 102                 xbt_swag_offset(elem, active_element_set_hookup));
 103
 104   cnst->bound = bound_value;
 105   cnst->usage = 0;
 106   insert_constraint(sys, cnst);
 107
 108   return cnst;
 109 }
 110
 111 void lmm_constraint_free(lmm_system_t sys, lmm_constraint_t cnst)
 112 {
 113   remove_constraint(sys, cnst);
 114   lmm_cnst_free(sys, cnst);
 115 }
 116
 117 lmm_variable_t lmm_variable_new(lmm_system_t sys, void *id,
 118                                 xbt_maxmin_float_t weight,
 119                                 xbt_maxmin_float_t bound,
 120                                 int number_of_constraints)
 121 {
 122   lmm_variable_t var = NULL;
 123
 124   var = xbt_new0(s_lmm_variable_t, 1);
 125   var->id = id;
 126   var->cnsts = xbt_new0(s_lmm_element_t, number_of_constraints);
 127   var->cnsts_size = number_of_constraints;
 128   /* var->cnsts_number = 0; *//* Useless because of the calloc  */
 129   var->weight = weight;
 130   var->bound = bound;
 131   var->value = -1;
 132   insert_variable(sys, var);
 133
 134   return var;
 135 }
 136
 137 void lmm_variable_free(lmm_system_t sys, lmm_variable_t var)
 138 {
 139   remove_variable(sys, var);
 140   lmm_var_free(sys, var);
 141 }
 142
 143 xbt_maxmin_float_t lmm_variable_getvalue(lmm_variable_t var)
 144 {
 145   return (var->value);
 146 }
 147
 148 void lmm_expand(lmm_system_t sys, lmm_constraint_t cnst,
 149                 lmm_variable_t var, xbt_maxmin_float_t value)
 150 {
 151   lmm_element_t elem = NULL;
 152
 153   if (var->cnsts_number >= var->cnsts_size)
 154     abort();
 155
 156   elem = &(var->cnsts[var->cnsts_number++]);
 157
 158   elem->value = value;
 159   elem->constraint = cnst;
 160   elem->variable = var;
 161
 162   insert_elem_in_constraint(elem);
 163
 164   make_constraint_active(sys, cnst);
 165 }
 166
 167 lmm_constraint_t lmm_get_cnst_from_var(lmm_system_t sys, lmm_variable_t var, int num)
 168 {
 169   if(num<var->cnsts_number) return(var->cnsts[num].constraint);
 170   else return NULL;
 171 }
 172
 173 int lmm_get_number_of_cnst_from_var(lmm_system_t sys, lmm_variable_t var)
 174 {
 175   return(var->cnsts_number);
 176 }
 177
 178 void *lmm_constraint_id(lmm_constraint_t cnst)
 179 {
 180   return cnst->id;
 181 }
 182
 183 void *lmm_variable_id(lmm_variable_t var)
 184 {
 185   return var->id;
 186 }
 187
 188 static void saturated_constraints_update(lmm_system_t sys,
 189                                          lmm_constraint_t cnst,
 190                                          xbt_maxmin_float_t * min_usage)
 191 {
 192   lmm_constraint_t useless_cnst = NULL;
 193
 194   if (cnst->remaining <= 0)
 195     return;
 196   if ((*min_usage < 0) || (*min_usage > cnst->remaining / cnst->usage)) {
 197     xbt_swag_t active_elem_list = &(cnst->active_element_set);
 198
 199     *min_usage = cnst->remaining / cnst->usage;
 200
 201     while ((useless_cnst = xbt_swag_getFirst(&(sys->saturated_constraint_set))))
 202       xbt_swag_remove(useless_cnst, &(sys->saturated_constraint_set));
 203
 204     xbt_swag_insert(cnst, &(sys->saturated_constraint_set));
 205   } else if (*min_usage == cnst->remaining / cnst->usage) {
 206     xbt_swag_insert(cnst, &(sys->saturated_constraint_set));
 207   }
 208 }
 209
 210 static void saturated_variables_update(lmm_system_t sys)
 211 {
 212   lmm_constraint_t cnst = NULL;
 213   xbt_swag_t cnst_list = NULL;
 214   lmm_element_t elem = NULL;
 215   xbt_swag_t elem_list = NULL;
 216
 217   cnst_list = &(sys->saturated_constraint_set);
 218   while ((cnst = xbt_swag_getFirst(cnst_list))) {
 219 /*   xbt_swag_foreach(cnst, cnst_list) { */
 220     elem_list = &(cnst->active_element_set);
 221     xbt_swag_foreach(elem, elem_list)
 222         xbt_swag_insert(elem->variable, &(sys->saturated_variable_set));
 223     xbt_swag_remove(cnst, cnst_list);
 224   }
 225
 226 }
 227
 228 void lmm_solve(lmm_system_t sys)
 229 {
 230   lmm_variable_t var = NULL;
 231   lmm_constraint_t cnst = NULL;
 232   lmm_element_t elem = NULL;
 233   xbt_swag_t cnst_list = NULL;
 234   xbt_swag_t var_list = NULL;
 235   xbt_swag_t elem_list = NULL;
 236   xbt_maxmin_float_t min_usage = -1;
 237
 238   /* Init */
 239   var_list = &(sys->variable_set);
 240   xbt_swag_foreach(var, var_list) {
 241     var->value = -1;
 242   }
 243
 244
 245   /* Compute Usage and store the variables that reach the maximum */
 246
 247   cnst_list = &(sys->active_constraint_set);
 248   xbt_swag_foreach(cnst, cnst_list) {
 249     /* INIT */
 250     elem_list = &(cnst->element_set);
 251     cnst->remaining = cnst->bound;
 252     cnst->usage = 0;
 253     xbt_swag_foreach(elem, elem_list) {
 254       cnst->usage += elem->value / elem->variable->weight;
 255       insert_active_elem_in_constraint(elem);
 256     }
 257
 258     /* Saturated constraints update */
 259     saturated_constraints_update(sys, cnst, &min_usage);
 260   }
 261
 262   saturated_variables_update(sys);
 263
 264   /* Saturated variables update */
 265
 266   do {
 267     /* Fix the variables that have to be */
 268     var_list = &(sys->saturated_variable_set);
 269
 270
 271     xbt_swag_foreach(var, var_list) {
 272       /* First check if some of these variables have reach their upper
 273          bound and update min_usage accordingly. */
 274       if ((var->bound > 0) && (var->bound / var->weight < min_usage)) {
 275         min_usage = var->bound / var->weight;
 276       }
 277     }
 278
 279
 280     while ((var = xbt_swag_getFirst(var_list))) {
 281       int i;
 282
 283       var->value = min_usage / var->weight;
 284
 285       /* Update usage */
 286
 287       for (i = 0; i < var->cnsts_number; i++) {
 288         elem = &var->cnsts[i];
 289         cnst = elem->constraint;
 290         cnst->remaining -= elem->value * var->value;
 291         cnst->usage -= elem->value / var->weight;
 292         remove_active_elem_in_constraint(elem);
 293       }
 294       xbt_swag_remove(var, var_list);
 295     }
 296
 297     /* Find out which variables reach the maximum */
 298     cnst_list = &(sys->active_constraint_set);
 299     min_usage = -1;
 300     xbt_swag_foreach(cnst, cnst_list) {
 301       saturated_constraints_update(sys, cnst, &min_usage);
 302     }
 303     saturated_variables_update(sys);
 304
 305   } while (xbt_swag_size(&(sys->saturated_variable_set)));
 306 }
 307
 308 /* Not a O(1) function */
 309
 310 void lmm_update(lmm_system_t sys, lmm_constraint_t cnst,
 311                 lmm_variable_t var, xbt_maxmin_float_t value)
 312 {
 313   int i;
 314   lmm_element_t elem = NULL;
 315
 316   for (i = 0; i < var->cnsts_number; i++)
 317     if (var->cnsts[i].constraint == cnst) {
 318       elem->value = value;
 319       return;
 320     }
 321 }
 322
 323 void lmm_update_variable_bound(lmm_variable_t var,
 324                                xbt_maxmin_float_t bound)
 325 {
 326   var->bound = bound;
 327 }
 328
 329 void lmm_update_variable_weight(lmm_variable_t var,
 330                                 xbt_maxmin_float_t weight)
 331 {
 332   var->weight = weight;
 333 }
 334
 335 void lmm_update_constraint_bound(lmm_constraint_t cnst,
 336                                  xbt_maxmin_float_t bound)
 337 {
 338   cnst->bound = bound;
 339 }
 340
 341 int lmm_constraint_used(lmm_system_t sys, lmm_constraint_t cnst)
 342 {
 343   return xbt_swag_belongs(cnst,&(sys->active_constraint_set));
 344 }
 345
 346
 347 /* void lmm_print(lmm_system_t sys) */
 348 /* { */
 349 /*   lmm_variable_t var = NULL; */
 350 /*   lmm_constraint_t cnst = NULL; */
 351 /*   lmm_element_t elem = NULL; */
 352 /*   xbt_swag_t cnst_list = NULL; */
 353 /*   xbt_swag_t var_list = NULL; */
 354 /*   xbt_swag_t elem_list = NULL; */
 355
 356 /*   var_list = &(sys->variable_set); */
 357 /*   xbt_swag_foreach(var, var_list) { */
 358 /*     printf("%s : {\n",var->id); */
 359 /*     printf("\t %s : {\n",var->id); */
 360 /*   } */
 361 /* } */